[STUMP] rotate windows

[Eric Abrahamsen]

I've seen a couple of functions online for rotating top windows through
frames, but none of the code seems to work with StumpWM from git. Here's
what I've got, but at least `group-frames' is undefined:

;(defun shift-windows-forward (frames win)
;  (when frames
;          (let ((frame (car frames)))
;                 (shift-windows-forward (cdr frames)
;                                        (frame-window frame))
;                 (when win
;                         (pull-window win frame)))))

;(defcommand rotate-windows () ()
;  (let* ((frames (group-frames (current-group)))
;           (win (frame-window (car (last frames)))))
;          (shift-windows-forward frames win)))

Can anyone tell me how I might update this for the most recent version
of stump?

Thanks!
Eric